Pulp-feed regulator



Sept. 3, 1929.

G. E. MAYO PULP FEED REGULATOR Filed 0G13. l, 1928 Imvcntor EM Gtorncg S6 -Fourdrinier screen or refininfg r Patented Sept. 3, 1929i.

GEORGE E. IAYQ OF POTSDAI, NEW YORK.

PULP-FEED REGULATOR.

Application illed October 1, 1938. Serial N0. 809,670. y l

The invention relates to the art of paper making, and more particularlyto an improved device for controlling the rate of iiow of semi-liquidpulp from a stuff .box to a engine.

In the making of paper om ulp it is necessary that the-amount of solimaterial in the pulp from the stuff box or chest be delivered to theFourdrinier screen at a deli; nitely fixed rate Iin order that thefinished sheet of paper be pf uniform thickness. For the urpose ofobtaining such a constant feed or ow` from a stuff box to a Fourdrinierscreen or refining engine, it has been sug-l gested to provide means forautomatically controllin the volume of the pul delivered per unit 0%time, but this method as the disadvantage of merely controlling thevolume of the pul delivered per A unit of time without provi ing anymeans for cpmpensatin for the variations in the pulp mixture itsel It isobvious that, when the rate of feed of the entire ulp mixture ismaintained constant and t e `ratio of solid to water in the mixturevaries, the amount of solid delivered to the screen per unit of timewill also vary and will result in variations in the thickness of thefinished paper. f

In Letters Patent No. 1,248,972, of December 4, 1917, granted to I. J.Witham and myself, we described a device for controlling the A feed froma stuff box to a Fourdrinier screen container was built up in varyingdegree in level of the pulp in the stuff-box being in this in such awayas to cause a substantiall constant amount of solid material to bedelivered per unit of time, the device being so'arranged as tocompensate for variations of the ratio of solid to water in the mixture.Brieiiy stated, the device described in the above mentioned patentconsisted of 'a hollow conical air container suspended in a stu box 'andimmersed in the mixture contained therein with its base alone open tothe mixture.. The air container mentioned was connected with a source'ofcom ressed .air supply which delivered air to t e container at as nearlya constant rate as possible and at a pressure sufficient to prevent themixture from ascending into'the container, the air from within thecontainer instead continuously escaping therefrom. Due to the fact thata pulp mixture of var 'ng consistency or density offered greateror essresistance to the escape of air from the container, the pressure withinthe accordance with the ratio of pulp to water in the mixture, whichratio determines the density of. the pulp mixture. B connecting thecontainer to an air-operate controlling the pul feed ate controllin flowof pulp from t e stuff ox we utilize the varying pressure in thecontainer to control the feed of pulp in such a way that, though avarying quantity of mixture was delivered per unit of time, the rate ofiow f solid material to the Fourdriner screen was maintainedsubstantially constant.

While the above described device has worked admirably, it has been founddiicult to furnish compressed air to the container at va perfectlconstant rate,"s0 that at times the rate of ow of pulp from the stuffbox has been influenced not only by the ratio of mechanism pulp to waterin the mixture but also by the by the ratio of solid to water in thepulp mixture," whereby variations the ,ratio cause a greater or lessamount of pulp to flow from the stuff box so that the rate of flow of lsolid material from the stuff., box is always constant. A

Another ob'ect of this invention is to rovide Imeans o the characterdescribed w ich requires a minimum of attention and whichvis sim le andeconomical to construct.

ith these and other objects in view, the I nature of which will more4fully appear, the invention will be more clearl understood by a readingof the following etailed description, the appended claims, and the twoviews villustrated in the accompanying drawings, in which: f L if Figure1 is a plan view of-a stuffbox embogymg my invention, pand igure 2 is avertical sectional view taken on the line 2-2 of Figure 1.

Like numerals desi ate corresponding parts in the two views illustrated.

\ In the-drawings there is shown a stu box A filled with ulp B which isintroduced into the stu box t rough a pipe C from a um or other sourceof supply (not shown he stuff box is provided with an overow partition 1by means of which excess pulp is discharged into a pipe l2 through whichthe excess 1s led back to the source of supply, the

way maintained constant, regardless of the amount of pulp being used.The stuff box is further provided with a discharge opening 1 acrosswhich extends a strainer grid 1", the rate of discharge or feed of pulpthrough the opening being controlled by a pulp feed gate 1 journaled inbearings 1d in the strainer grid 1b.

Suspended within the stuftn box by any suitable means and extending intothe pulp B is an air container 3. The said container ,is open to thepulp at a point below the level thereof, preferably at its lower end,but closed at its upper end by the plate 5. The plate 5 may be providedwith a flange 6 for attaching it to the container 3.

In the drawings I have shown the air container'3 as of cylindricalshape, though of course a container of any other shape such asrectangular, or triangular shape in cross section, could also be used.

A casing 7 is rigidly mounted upon the stud box by means of brackets 8,and in this casin is located a diaphragm 9 comprising top an bottomplates 10 and 11 respectively and collapsible side walls 12, the bottomplate11 being fixed to the bottom ofthe casing7, while the top plate 10and the side wall 12 are spaced from the adjacent walls of the casingandare free to move 'relative to the casing and at the urge of airpressure within the diaphragm chamber formed between the plates 10 and11 v and walls 12. The diaphragm chamber is designated 9 andcommunicates with the interior of the air container 3 by means of a pipeline 13 which enters the container at 14 and the diaphragm chambervat15, a valve 16 being interposed in the pipe line for shutting offcommunication of the diaphragm with the air container when desired. Agate operating arm 17 is fulcrumed toa bracket 18 on the casing 7, as at19, and extends from the fulcrum 19 across and beyond the stuff box. Adiaphragm arm 20 is' pivoted at one end to a pair of lugs 21 on thecasing 7 and is provided at its other end with a boss 22 which extendsthrough thetop of the casing 7 and rests upon the top plate 10 of thediaphragm to move up and down therewith. Slidably mounted on the gateoperating arm is an abutment 23 which may be locked in any desiredlposition of adjustment by means of a set screw 23a. The arm 17 overliesthe arm 20 so that this abutment rests uponthe diaphragm arm 20 andcauses the gate operating arm 17 to be rocked about the fulcrum 19 whenthe` diaphragm top plate.10 is moved up or down in a mannerto behereinafter described. Obviously, by changing the position of theabutment 23 relative tothe p1vot 21 and the fulcrum 19, the amount ofmovement'imparted to the gate operating arm 17 by a given moveent of thed1aphragm arm 20 may be varied.

At the outer end of lthe gate operating arm 17 a number of weights 24 isadjustably slidably carried and serves to urge the buter end of the saidarm 17 downwardly. A link 25 provided with a link adjusting turnbuckle25a is pivoted at one of its ends to the gate operating arm 17 as at 26and has its other end connected to a lifting ring 27 on the gate 1 forraising and lowering the said gate as the gate operating arm 17 israised or lowered in a` manner to be presently described.

In the drawings there is also shown a pressure gauge 28 of conventionaltype mounted on the top plate 5 of the air container 3, the said augecommunicating with the container and being actuated by the pressuretherein.

The manner of operation of the device may be briefly described asfollows: It is assumed that the valve 16 has been opened to allow theinterior of the air container 3 to communicate with the diaphragm 7..Pulp is then introduced into the stuff box through the pipe C, and',rising in the stuff box, will entrap a quantity of air in the container.When the pulp on the outside of the container has reached the levelshown in Figure 2 it will overflow the partition 1 and be maintainedat-this level as previously described. Due to the pressure exerted bythe column of pulp in the stuff box, some of the pulp will rise withinthe air container 3 and compress thel air entrapped therein, the risingof the pulp inside of the said container stopping' at such a level thatthe pressure exerted by the entrapped and compressed air is justbalanced by the otherwise unbalanced head of pulp indicated at h.Assuminor that the pulp so initially introduced is of the proper workingconsistency, the abutment 23 and the weights 24 are then adjusted alongthe gate operating arm so as to cause the gate 1 to be held in such anopen position as will allow the rate of flow of pulp from the stuff box,which will result'in deliverying the solid material at the desired rate.As long as the ratio of solid material to water in the pulp mixtureremains constant, the pressure of the air entrapped in the container 3will remain the same and the gate 1 will remain stationary, thuspermitting a constant feed of pulp, and, since the ratio of solid towater is constant, a constant feed of solid material will likewise beassured.

If, however, the ratio of solid material to water in the pulp decreases,it will be necessary to open the gate farther to allow a greater feed ofpulp in order to still feed solid material at the same rate. Thegatewill be automatically opened as follows: When the ratioy of solid matterto water decreases, the densit of the pulp mixture will increase due tot e fact that water has a higher specific gravity than the solidmaterial used. The increase in density of the pulp will result in agreaterA upward pressure being exerted b' the pul due to the head of pup indicate at h, an the level of the pulp within the container willthereby be raised until the entrapped air has been compressed to such adegree as will balance the diminished head of pulp L. The increasedpressure of the air in thecontainer acts throughthe pipe 18 and on theunder side of the diaphragm plate 10, raising the plate, which, by

means of the diaphragm arm 20 and the abut? ment 23, will in turn movethe outer end of the gate operating arm upward to lift the gate andallow a greatery feed of -pulp from the stuf'll box to compensate by anincreased volume flow of pulp of gre'aters density for a will bedelivered from the stuff box.

y The gauge 28, being actuated by air under pressure in the aircontainer 3, can be calibrated to accurately indicate the ratio of solidmaterial to water in the pulp mixture, since the pressure in thecontainer is entirely dependentl upon this ratio.

It will be gathered from the foregoing that the container 3 is in thenature of an air trap in which an unchanging body of air is trapped bythe pulp in the stuff box and compressed in degree according to theconsistency of the said pulp. v x

It is apparent. that I have provided a device Iwhich may be used tocontrol the feed 'of pulp from a stuff box in such a way as will insurea constant feed of solid material regardless of variations in theconsistency of the pulp. My device is extremely reliable and accurate,since for its operation it depends only upon -the consistency ofthe pulpand not upon any outside influences which Amight be subject to continuedvariations l tending to reduce the efiiciency of the device. f

It is obvious that my pulp feed regulator may be used in connection withthe feeding of other mixtures of solid matter and liquid, and it. is ofcourse to be understood that 'the details of structure and arrangementsY pulp solid flowing through the feed gate per' given time unit, saidoperating means including an air container confining an unchanging bodyof air therein and open to the pulp at a point below its level in thestuff box, and pressure responsive means communicating with thecontainer and actuated by the pressure of the air confined therein forpositioning the gate and regulating the flow of pulp from the dischargeopenmg.

2.' In a pulp feed regulator, the combination with a stuff box having apulp discharge opening, of a pulp feed gate, and means for operating thegate to regulate the amount of pulp solid flowing through the feed gateper vgiven time unit, saidoperating means including a fluid containerconfining an unchanging body of fluid therein and open to the pulp at apoint below its level in the stuff box, and pressure responsive meanscommunicating with the container and actuated by the pressure of thefluid confined therein for positioning the gate and regulating the flowof pulp from the discharge opening.

3. In a pulp feed regulator, the combination with a stuff box havingmeans for maintaining a constant level of pulp therein, and a pulpdischarge opening, of a pulp feed gate, and means for operating the gateto regulate the amount of pulp solid flowing through the feed gate pergiven time unit, said operating means including an air containerconfining an unchanging body of air therein and open to the pulp at apoint below 4 its level in the stuff box, and pressure responsive meanscommunicating with the container and actuated by the pressure of the airconfined therein for positioning the gate and regulating the flow ofpulp from the discharge opening.

4. In a 1pulp feed regulator, the combination with a stuff box having apulp discharge opening of a pulp feed gate and means for operating thegate including an air container within the stufll box and open tothe'pulp at a point below the level thereof for confining an unchangingbody of air within the container, pressure responsive means communieating with the container and actuated by the pressure of the airtherein, and adjustable means connected to said pressure responsivemeans and to the gate for operating the gate when the pressureresponsive means is actuated..

5. In a pulp feed regulator, the combination with a stuff box having apulp discharge opening of a pulp feed gate and means for operating thegate including an air container within the stud box and open to the pulpat a point. below the level thereof for confining an unchanging body ofair within the container, pressure responsive means communicating withthe container and actuated by the pressure of the air therein, a gateoperating arm, and means adjustably positioned on the arm and actuatedby the pres- 6. In a pulp feed regulator, the combina` i tion with'astuff box having aypulp discharge opening of apulp feed gate and meansfor operating the gate including an'air container within the stu' boxandopen to the pul atta point lbelow the level thereof lfor con ing anunchanging body of air within the container, pressure responsive meanscommunieating with the container and actuated by the pressure of the airtherein`,a gate operating arm, means adjustably positioned on the armand actuated by the pressure' responsive means for'operating the arm andthe gate, and weights adjustably positioned on the arm and serving tourge it downwardly.

7. Ina pulp feed regulator,`the"combina tionwith al stufl:` box havinga'pulp discharge opening of a pulp feed gate and means for op-A eratingthe gate including an air container within the stuff box and open to thepulp at a point below the level thereof for confining an unchangingbodyf of air within the container, a pressure responsive diaphragmcommunicating with the container and actuated by the pressure -of theair therein, a. piv-otedy` diaphragm. arm adapted to be actuated bycontact with the diaphragm, a pivoted gate operating arm overlying thediaphragm arm, an abutment adjustabf gate operating arm for contact withthe diaphragm arm, and means connecting the gate operating arm to thegate at a point remote from the pivot on said arm. f

8. In a pulp feed regulator, the combination with a stuff box having apulp discharge opening of a pulp feed gate and means for operating thegate including an air container Within the stuff box and open to thepulp at a point below the level thereof for confining an unchanging bodyof air within the container, a pressure responsive diaphragm communieating with the container and actuated by the pressure of the airtherein, a pivoted diaphragm arm adapted to be actuated by contact withthe diaphragm, a pivoted gate operatingarm overlying the diaphragm arm,an abutment adjustably positioned 'on the gate oplerating arm forcontact with the diap ragm arm, mea/ns connecting the gate operating armto the gate at a oint remote from the pivot on said arm, an adjustablemeans for urging the gate operating arm downwardly.

9. In a pulp feed regulator, the combination with a stuff box havingmeans for maintaining a constant level of pu'lptherein of y 1positioned. onl the u an air container within the stuff box and open tothe pulp at a point below the level thereof for confining an unchangingbody of air within the container, and a pressure indicating gaugecommunicating with the interior ofsaid container and responsive tothepressure therein.

' 10. In a pulp feed regulator wherein is provided a stuff box havin adischarge opening and a gate to control .t e opening;'means to trap anunchanging body of fluid in amanner for having its pressure varied inaccordance with variations in density of pulp in the stuff box, andmeans actuated by the pressure of the said body of fiuid to control theposition of Ithe said gate. u v y 11. In a pulp feed regulator, a stuffbox having means to maintain a constant level of pulp therein and a pulpdischarge opening, a

gate to cont-rol the discharge opening, a pressure actuated diaphragm, afluid trap open at one point to communication with the pul in the stuffbox beneath the level thereof an at another point with the diaphragmVand closed throughout otherwise to trap therein an unchanging body offluid in a manner for causing the pressure of the trapped fluid to varyin accordance with variations in the den- 4 lsity of the pulp in thestuff box, and means connected to the control gate and actuated by thediaphragm to position the gate according to the degree of density of thepulp in the stuff box.

12. In a pulp feed regulator wherein provided a. stuff box having adischarge opening and a gate to control the opening; means to trap anunchanging body of fluid in a manner for havin its pressure varied i'naccordance with varlations in density of pulp in the stuff box, andmeans actuated by thepressure of the said body of fluid to control theposition yof the said gate, said last named means comprising a pressureresponsive diaphragm communicating with the trapped body of fluid andactuated by the pressure of the said bod Vof fluid, a pivoted diaphragmarm adapte to be actuated by contact with the diaphragm,

a pivoted gate operating arm overlying the diaphragm arm,'means toconnect the gate and gate operating arm for movement together, and anadjustable abutment member for causing the diaphragm arm and gateoperating arm to interengage for the purpose described. V

In testimony whereof, I have hereunto subscribed my name.

GEORGE E. MAYO.

